MSRA

MRSA stands for methicillin-resistant Staphylococcus aureus, which is a group of bacteria that live on the surface of people's skin and inside the nose. It is normally harmless: most people who are carrying it are totally unaware that they have it. The MSRA strains are are resistant to a number of antibiotics, including methicillin.

Open cuts or wounds are the typical means that the MSRA bacteria are able to enter the body. Those with weakened immune systems, including those who have undergone surgery or been ill, may develop symptoms that have the potential to develop into seriouos problems.

Alzheimer's Disease

Alzheimer's disease is a progressive neurologic disease of the brain leading to the irreversible loss of neurons and the loss of intellectual abilities, including memory and reasoning, which become severe enough to impede social or occupational functioning. Alzheimer's disease is also known as simply Alzheimer's, and Senile Dementia of the Alzheimer Type (SDAT) .

Osteoporosis

The bones of people with osteoporosis become thin and weak. The word "osteo" comes from the Greek osteon meaning "bone", while "porosis" comes from the Greek poros meaning "hole, passage". According to Medilexicon's medical dictionary, osteoporosis is a "reduction in the quantity of bone or atrophy of skeletal tissue; an age-related disorder characterized by decreased bone mass and loss of normal skeletal microarchitecture, leading to increased susceptibility to fractures."

Pixel Count (Resolution)

Differences in cameras is responsible for differences in pixel count. With resolution ranging from 512 x 512 to 1024 x 1024, not all cameras are equal. The pixel count of a CCD camera in an OEC 9800, for example, is 980 x 980, 768 x 494 in a Quantum or 1024 x 1024 in a Pulsera or Ziehm Vision.

X-Ray TV Camera

Initial C-arms made by market leader OEC, the OEC 9000 and OEC 9400, both used analog (Vidicon) cameras. Other vendors such as Philips and Siemens and Ziehm used CCD cameras. Today almost all C-arms have CCD cameras. These high-quality lens' provide more light to the camera. Ziehm introduced a spectrally responsive CCD camera that translate to a more sensitive camera requiring less dose.

Collimation

OEMs differ on methods of collimation. Types used include: translucent blades, solid tungsten shutters, full lead shutters.  The translucent blades with tapered edges permit soft tissue visualization around long bone or spine and aids in placement of needle and screw alignment. Nearly all C-arms have both iris and parallel shutter positions and ratation indicators.

Anode Heat Capacity and Cooling

Heat capacity and dissipation are limiting factors in heat management. Higher heat capacity in the housing generally translates to the ability to do many high dose procedures back to back. As many practices schedule high patient volume on specific days of the week, this is an important consideration. Also important is the anode cooling rate.

Anode Tubes

The combination of power (kW), anode angle and focal spot size dictate the use of stationary or rotating anodes. Mobile C-arm fluoroscopic applications are sufficiently handled by a stationary anode and 0.6mm focal spot. The use of 0.3mm focal spot mandates the use of a rotating anode.  

Focal Spot Fluoro

Focal spot size, measured in mm. directs image quality to a large extent. The smaller the focal spot, the better the image resolution. However, it is important to consider the image matrix of the system. For example, a 1k x 1k matrix with 0.3mm focal spot will produce approximately the same resolution as a 0.6mm focal spot at object-to-image distances of 40cm or less. Therefore, in C-arm imaging with 1k x 1k matrix, the performance of a 0.6mm is equal to a 0.3mm.

Image Intensifier

The standard image intensifier is 9"/6". Most systems built after mid-90s have tri-mode IIs with 9"/6"/4.5" IIs.  When considering field of view, it can be said that the smalles, 4.5" is not clinically necessary and not worth the trade-off of higher dose. Manufacturers use technical aspects of the camera and lens assembly in order to more efficiently provide an image, some resulting in comparatively lower dose in the 4.5 field of view.